The long-term goal of the proposed program is to overcome the problem of immunologic rejection of therapeutic renal allografts in man. The main research aims are: (1) to apply advances in basic immunogenetics research to therapeutic tissue and organ transplantation in patients; (2) to improve thereby the success rate of such treatment; and (3) to utilize materials and information derived from patients to contribute to further immunogenetic advances. Emphasis presently is on (a) defining additional specificities of HLA system; (b) assessing the relative antigenicity of HLA haplotypes; (c) determining the importance of the immunologic reactivity of the recipient on acceptance of the allograft; and (d) immunopathologic mechanisms of kidney disease and allograft rejection. A number of nonimmunologic studies are also being pursued in this multidiscipline program as follows: renal reservation in vitro; parathyroidectomy and parathyroid grafts in the management of secondary hyperparathyroidism of renal osteodystrophy; mental disorders of renal allograft donors and recipients; and infections associated with immunosuppression.